Heuchera plant named ‘Pistache’

ABSTRACT

A new cultivar of hybrid  Heuchera  named ‘Pistache’, characterized by its lime green to yellow foliage, its large broadly ovate shaped, wavy leaves, its compact and low mounded plant habit, its tolerance to heat and humidity and its hardiness at least in U.S.D.A. Zones 4 to 9.

Botanical classification: Heuchera hybrid.

Cultivar designation: ‘Pistache’.

CROSS REFERENCE TO A RELATED APPLICATION

This application is co-pending with U.S. Plant Patent applications filed for sibling plants derived from the same cross in the inventor's breeding program that are entitled Heuchera Plant Named ‘Pinot Noir’ (U.S. Plant patent application Ser. No. 12/002,889), Heuchera Plant Named ‘Encore’ (U.S. Plant patent application Ser. No. 12/008,941) Heuchera Plant Named ‘Pinot Gris’(U.S. Plant patent application Ser. No. 12/008,928), Heuchera Plant Named ‘Tiramisu’ (U.S. Plant patent application Ser. No. 12/002,921), and Heuchera Plant Named ‘Beaujolais’ (U.S. Plant patent application Ser. No. 12/008,338).

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of hybrid Heuchera, botanically known as a Heuchera of hybrid origin and is hereinafter referred to by the cultivar name ‘Pistache’.

The new cultivar was derived from a controlled breeding program by the inventor in Hantay, France. The inventor made a cross in summer of 2005 between Heuchera ‘Gloire d'Orelans’ (not patented, syn. Heuchera×brizoides ‘Gloire d'Orleans’) as the male parent and Heuchera×villosa ‘Caramel’ (U.S. Plant Pat. No. 16,560) as the female parent. The goal of the breeding program was to obtain unique cultivars of Heuchera that combined the flowering habit of ‘Gloire d'Orleans’ with the vigor and unique foliage coloration of Heuchera×villosa. The inventor selected ‘Pistache’ in 2006 as a single unique plant amongst the seedlings that resulted from the above cross.

Asexual reproduction of the new cultivar was first accomplished under direction of the inventor by in vitro propagation in Rijswijk, The Netherlands in winter of 2007. Asexual reproduction of the new cultivar by division and tissue culture has shown that the unique features are stable and reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

The following traits have been repeatedly observed and represent the characteristics of the new cultivar. These attributes in combination distinguish ‘Pistache’ as a new and unique cultivar of Heuchera.

-   -   1. ‘Pistache’ exhibits unique foliage with leaves that are         lime-green in color in spring and fall and yellow (chartreuse)         in color during the summer months.     -   2. ‘Pistache’ exhibits large, broadly ovate shaped, wavy leaves.     -   3. ‘Pistache’ has a more vigorous growth habit in comparison to         other yellow foliaged Heuchera.     -   4. ‘Pistache’ is tolerant to high heat and humidity imparted by         having Heuchera×villosa in its parentage.     -   5. ‘Pistache’ is cold hardy at least in U.S.D.A. Zones 4 to 9.

‘Pistache’ differs from its parent plants in that ‘Caramel’ is a ×villosa hybrid and has foliage that is yellow-orange in color and ‘Gloire d'Orleans’ is a ×brizoides hybrid with green foliage.

‘Pistache’ can be compared to Heuchera ‘Citronelle’ (U.S. Plant Pat. No. 17,934) and ‘Lime Rickey’ (U.S. Plant Pat. No. 16,210) for its similarity in leaf color, however, ‘Pistache’ has larger leaves and a more vigorous growth habit than both ‘Citronelle’ and ‘Lime Rickey’. The closest comparison plants in overall leaf shape, habit, and performance are its sibling cultivars that differ in foliage coloration; ‘Pinot Noir’ has dark purple-grey foliage, ‘Encore’ has rose-purple foliage, ‘Pinot Gris’ has foliage that emerges orange-yellow in spring and changes to a rose color with a silvery overlay in summer, ‘Tiramisu’ has foliage that is yellow-green with red mottling, and ‘Beaujolais’ has foliage that is burgundy red with a silver overlay.

BRIEF DESCRIPTION OF THE DRAWING

The acompanying colored photographs illustrate the overall appearance and distinct characteristics of the new Heuchera. The photographs were taken in mid summer of plants six months in age as grown in a 2-liter container in The Netherlands.

The photograph on the first sheet provides a side view of the plant habit and typical mid summer coloration of the foliage of ‘Pistache’.

The photograph on the second sheet provides a close-up view of a leaf of ‘Pistache’.

The colors in the photographs are as close as possible with the photographic and printing technology utilized. The color values cited in the detailed botanical description accurately describe the colors of the new Heuchera.

DETAILED BOTANICAL DESCRIPTION OF THE PLANT

The following is a detailed description of six month-old plants of the new cultivar grown two in a 2-liter container outdoors in The Netherlands. Plants were grown under average day temperatures of 12° to 39° C. and average night temperatures of 5° to 16° C. The phenotype of the new cultivar may vary with variations in environmental, climatic, and cultural conditions, as it has not been tested under all possible environmental conditons. The color determination is in accordance with the 2001 R.H.S. Colour Chart of The Royal Horticultural Society, London, England, except where general color terms of ordinary dictionary significance are used.

-   General description:     -   -   Plant habit.—Compact, low mounding, clump-forming herbaceous             perennial.         -   Height and spread.—Reaches a height of about 12.2 cm in             height and about 33.2 cm in width.         -   Hardiness.—At least in U.S.D.A. Zones 4 to 9.         -   Culture.—Full sun to medium shade in moist'well-drained,             fertile soils, tolerant to high heat and humidity.         -   Diseases and pests.—Disease free in the conditions tested,             no susceptibility or resistance to pests has been observed.         -   Root description.—Fibrous roots on woody rootstalks.         -   Branching habit.—Basal rosettes of leaves on petioles.         -   Propagation.—In vitro propagation is the preferred method,             division are also possible.         -   Root initiation.—Roots appear in rooting media in 10 days at             20° C. in the laboratory without supplemental lighting.         -   Root development.—Rooted transplants from tissue culture             fully develop in a 2.5 inch container in about 20 days in a             greenhouse with average temperatures of about 20° C. without             supplemental lighting in The Netherlands.         -   Growth rate.—Moderate but more vigorous than is typical for             yellow-foliaged Heucheras, grows about 5 cm per month in             spring, with an average crop time of 20 weeks to develop in             a 9 cm container. -   Foliage description:     -   -   Leaf shape.—Broadly ovate in overall shape.         -   Leaf division.—Simple.         -   Leaf base.—Hastate, moderately overlapping.         -   Leaf apex.—Abruptly acute.         -   Leaf venation.—Primary palmate, secondary net-veined, not             conspicuous, vein color on upper surface 9B to 9C, vein             color on lower surface 150D to 154D.         -   Leaf margins.—Lobed with an average number of 7 lobes, lobe             margins crenate.         -   Leaf attachment.—Petiolate.         -   Leaf arrangement.—Basal rosettes.         -   Leaf orientation.—Held nearly horizontal to petiole,             slightly wavy.         -   Leaf surface.—Upper and lower surfaces are moderately             covered with short hairs with an average of 0.9 mm in length             and 155C in color, surface is slightly rough to touch.         -   Leaf color.—Spring upper surface; 150B, spring lower             surface; 151D, summer upper surface; 8A to 8B, summer lower             surface; 10B, fall upper surface; 144C, fall lower surface;             144D.         -   Leaf size.—Average of 10.1 cm in length and 9.9 cm in width.         -   Leaf quantity.—Average of 12 leaves per 2-liter container.         -   Petioles.—Round in shape, average of 11.2 cm in length and 2             mm in width, color is 150B tinged at base with 182D, surface             is villose with abundant hairs about 1.5 mm in length and             155C in color.         -   Stipules.—Present on each side of petiole base, about 8 mm             in length and 2 mm in width, color is 155B tinged with 182B. -   Flower and seed description: Flowering plants were not available for     data collection, racemes of white to pink bell-shaped flowers     typical of Heuchera should be expected under the right conditions     for flowering as they were reported to be observed on the original     plant. 

1. A new and distinct cultivar of Heuchera plant named ‘Pistache’ as herein illustrated and described. 